I'm looking at insulating my floor which will vary from 1 to 4 ft above ground. A previous topic suggested covering the bottom with tyvek, pegboard or osb/plywood with vent holes drilled. I'v got a chance to get a bunch of vinyl soffit free. It provides the venting and won't wick moisture like masonite pegboard. Since it's free it's my cheapest option. I'll only need to buy about 20% of my requirement. Any bad consequences here?
That would be a sturdy material that will not trap moisture. Be sure the insulation fully fills the joist cavity and the soffit material holds it up against the subfloor.
Good find!
Assuming that you're using batts, which way should the insulation's backing face? Do you need to install this before laying down the subfloor decking?
Vapor barrier to the warm side of the bats ie between bats and floor decking. I'm doing it from above before installing the decking because I have little room to work underneath. The trick is keeping the bats dry until the building is weather tight. Got my tarps ready for rain!!